1. Field of the Invention
This invention relates to sunscreens, and more particularly, to sunscreens for protecting the interior of motor vehicles against the sun's rays.
2. Description of Related Art
Sunscreens for motor vehicles can be categorized into two categories. The first category covers sunscreens that are intended to keep the sun's rays from damaging the interior of the vehicle or to prevent the interior of the vehicle from becoming excessively hot when the vehicle is not in use. The second category covers sunscreens that are intended to protect occupants of the vehicle from irritating rays of the sun when the vehicle is in use. The present invention relates to both categories of sunscreens.
A well known sunscreen of the first category is disclosed in U.S. Pat. No. 4,202,396, issued to Levy on May 13, 1980. That patent discloses a foldable sun shield for motor vehicles that comprises a substantially rectangular piece of cardboard that is folded along a plurality of fold lines extending in the vertical direction so that the sun shield can be folded into a small package for storage and then unfolded into a shape that approximately fits the front windshield of an automobile. Disadvantages of this device include the fact that the disclosed sun shield does not fit exactly within most windshields, thus allowing some of the sun's rays to come in around the shield; the device is difficult to mount in some motor vehicles, particularly those wherein the rear view mirror is mounted to the windshield directly; and the disclosed sun shield is easily bent or damaged thus destroying its effectiveness.
Another automobile sun shield of the first category is disclosed in U.S. Pat. No. 4,790,591, issued to Miller on Dec. 13, 1988. That patent discloses a flexible sheet comprised of a metallized plastic film that is specifically formed to the exact shape of a windshield. The flexible sheet is provided at several locations with one-half of a conventional hook and loop (VELCRO) fastener. The other half of the hook and loop fastener is mounted on the windshield of the automobile at locations corresponding to the locations on the flexible sheet having the other halves of the hook and loop fasteners. Disadvantages of that windshield screen include the fact that the flexible sheet must be custom designed for each model of automobile, thus minimizing the ability to mass produce the windshield effectively; and that the placement of the hook and loop fasteners must be carefully aligned between the windshield and the flexible sheet.
U.S. Pat. No. 4,759,581, issued to McNamee on July 26, 1988 discloses a sunscreen similar to that disclosed by Miller. This sunscreen is primarily intended for use on recreational vehicles. It also suffers from the disadvantage of the Miller device in that it requires both halves of a hook and loop fastener, which must be carefully positioned on both the vehicle and the sunscreen.
Sunscreens of the second category, i.e., those intended to protect the occupants of the vehicle from irritating rays include the convertible sun visor disclosed in U.S. Pat. No. 4,690,451, issued to Killar on Sept. 1, 1987. That patent discloses a convertible sun visor that can be mounted to an automobile body interior with an auxiliary mount means, or which by the addition of accessory mounting clips can be secured to a conventional sun visor already mounted in an automobile. A disadvantage of the Killar sun visor is that it is difficult to install on an automobile.
Another sun visor for an automobile is disclosed in U.S. Pat. No. 4,172,613, issued to Furando on Oct. 30, 1979. The Furando visor includes a panel for straddling the rear view mirror mounted on the automobile windshield so as to prevent sun from shining through onto the driver from a location on the windshield between the two conventional sun visors. The Furando sun shield is mounted to the windshield by either suction cups or adhesive. The Furando sun visor performs the very limited function of only preventing sun from shining through between the two conventional sun visors.
There are also a large number of products on the market that are intended to be mounted to the side windows of an automobile in order to prevent sun from shining on an infant that is mounted in a car seat. Such devices are usually mounted to the windshield by means of suction cups or adhesive tape. Such sun shields are frequently expensive, difficult to mount, or difficult to remove and store when not in use.